Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 31 Dec 2014

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

8(5)

25(25)

30(-)

24(10)

0.4(4)

12(51)

South

5(3)

22(22)

16(-)

31(13)

0.4(4)

11(48)

East

7(4)

22(22)

7(-)

52(22)

0.2(2)

13(52)

West

3(2)

24(24)

14(-)

29(12)

0.5(5)

13(52)

Central

6(4)

20(20)

41(-)

24(10)

0.4(4)

10(42)

1-hr PM2.5 (µg/m3)b Readings on 31 Dec 2014

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

10

7

13

13

15

12

11

8

10

13

18

19

South

8

11

9

9

12

6

5

5

11

9

18

20

East

19

20

15

13

12

13

13

15

12

13

13

13

West

16

17

14

15

16

11

11

14

8

9

13

17

Central

8

10

10

7

6

7

10

10

10

9

11

15

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

14

20

10

9

12

8

11

14

9

13

16

-

South

21

20

11

13

12

17

9

8

8

10

10

-

East

14

13

16

16

12

13

9

14

8

9

14

-

West

15

18

12

9

15

14

9

10

6

10

16

-

Central

10

11

15

13

8

11

12

9

7

8

10

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
31 Dec 2014

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

49

52

51

51

50

46

44

42

42

43

49

53

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

55

55

54

53

51

50

48

47

40

40

43

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.